An OPG also demonstrates the number, position and growth of all the teeth including those that have not yet surfaced or erupted through the gum. This can be particularly useful to check hard to see areas like wisdom teeth, or the development of a child’s jaw and teeth. It is also often used to check your jaw joint, the TMJ (temperomandibular joint), sometimes called the CMA (cranio-mandibular articulation), especially if you grind your teeth.